Research On Rough Set Based Modelling For Controlling Of Alluminium Alloy Pulsed GTAW Process

Pulsed GTAW is an important metal's welding techiniques, which can be used to obtain the high quality welding bead, which can be used in such field as spaceflight. To meet the need of weld quality, one should control the dynamics of the weld process. So the extraction of the dynamic characteristic can always be an important research filed.Now, most work can concentrate on GTAW, especially the penetration control of weld pool. Because the penetration depends on the width of the weld bead, so the control of weld penetration can be conclude into the control of backside width of weld pool. Skilled welders can dynamically adjust the wled parameters by observing the weld pool, and then fufill the control of the penetration. But human cannot always work in the ardure work environment, so it is important of fulfill the automated control of weld process. But because weld process is a typical complex process, it is not easy to fulfill the process.Rough set theory is a new mathematical approach to deal with imprecision, vagueness and uncertainty. IPt uses lower and upper approximation of a concept to discover fundamental patterns in data. By interpreting the obtained results, it can be used in many ways. When applied it to generate system model, the system variable data is broken into a limited number of meaningful ranges, then, the tables of data are reduced to a minimum set of decision rules for predicting the next state or measurement. Thus, a usable system models from tables of systems data is produced. These days, it has been widely used in many fields where a large number of data is obtained and a system model is needed such as in medical data analysis. So it is a prospective approach to fulfill the intelligent control.In this work, based on the experiment data, the method of knowledge based modeling and control has been researched. We simulated the intelligent action of welder and provide the theorical and application foundation of the key technique of the intelligent welding technology.In chapter two, the basic concept of rough set theory has been introduced. In chapter three, the rough set based modeling method of almunium alloy pulsed GTAW process has been researched. In chapter four, the rough set based control method of almunium alloy pulsed GTAW process has been researched. And in chapter five, the experiments are conducted to demonstrate the effectiveness of the proposed control method.